Chronic alcohol-induced diseases are the third leading cause of death in the United States and thus, the biochemical bases underlying the observed effects of alcohol are of great interest. Despite this interest, the pathways of alcohol metabolism and the mechanism(s) by which their end products ultimately mediate ethanol-induced organ damage is not clear. Recently, a new family of ethanol metabolites, fatty acid ethyl esters, the products of esterification of fatty acids and alcohol, have been described. Studies suggest that these compounds may be biochemical mediators of alcohol-induced cellular damage. The goal of this five year proposal is to elucidate at the biochemical lvel their role as mediators of alcohol-induced organ damage. Methods for studying fatty acid ethyl esters are well-established and ongoing in the lab. Soluble and membrane bound activities utilizing free fatty acids and fatty acylCoA, respectively, have been demonstrated in rat liver. These activities will be purified and antibodies produced to detremine the contribution of both pathways to overall ethyl ester production. An inhibitor of fatty acid ethyl ester synthesis, which we have very recently demonstrated, will be identified and its role in controlling fatty acid ethyl ester production defined. The half life of these relativley long-lived alcohol metabolites will be determined and the subcellular site of their degradation established. Since triacylglycerol accumulation is one of the hallmarks of alcohol induced liver disease, it will be determined whether fatty acid ethyl esters alter cellular uptake, synthesis, secretion, or esterification of cholesterol. Ethyl esters alter cellular uptake, synthesis, secretion, or esterification of cholesterol. Ethyl esters are retained in adipose tissue and are synthesized by human blood. Thus, they may act as laboratory markers of ethanol ingestion. Their role as such in clinical and postmortem material will be studied. To facilitate screening of numerous samples for fatty acid ethyl esters, a rapid extraction method will be developed. In summary, the experiments described in this proposal will define the biochemical metabolism of a newly described family of ethanol metabolites and establish their role as markers of chronic alcohol ingestion.